Tube socket



Feb. 23, 1937. T. MARTIN TUBE SOCKET Filed Dec. 10, 1955 BYIMQIZ {J4ATTORNEY.

lJNl'lED states PATENT OFFICE TUBE SOCKET Thomas Martin,

third to Hugh E. McLennan,

Pittsburgh, Pa., assignor of one- Pittsburgh, Pa.

Application December 10, 1935, Serial No. 53,787

7 Claims.

The invention. relates generally to electric conductor sockets and isdirected more particularly to receptacle sockets for retaining neontubes and the like.

The present practice requires the use of insulating anchor posts forsupporting the ne of making up a neon sign on tube across the face ofthe sign. These supporting posts or anchor members are required to carrythe mechanical load of the tube which consists of its weight and theVibrations to which the tube is subjected. These posts are usuallyconstructed from a piece of glass tubing having an open trough on thetop thereof in which the neon tube rests and to which it is secured bymeans of tiewires. The other end of the post is usually provided with ametal base adapted to be secured to the face of the sign board. Incharacter these posts are analogous to the insulator art wherein atransmission line is secured by tie wires to the top of a porcelaininsulator mounted on a cross arm or. the like.

In both arts the vibration of th such insulators are a source of troubleand particularly in the neon art wherein e tube strains against therigid posts, causing the tube and/or the posts to break. Again inchanging neon sign letters one is required to remove all of these tiewires and perhaps supply new sign. This causes rial and labor.

posts for new letters on the considerable expense in mate- When it isnecessary to replace a broken tube or to substitute new letters in thesign such alterations also require manship. Owing is quite frequentlyskilled workto the location of the signs it difficult to make suchchanges with the present practice of mounting the neon tube.

The principal object of this invention is the provision of a conductorsocket or receptacle that is capable of supporting a neon tube withoutthe aid of the insulating'posts and tie wires or other additionalsupports and.

difiiculties.

thereby overcome these Another ob ect of my invention is the provisionof a. conductor socket that will insure low resistance contact betweenthe lead wires and the tube.

Another object is the provision of a conductor socket wherein a tube maybe readily removed therefrom or inserted therein by an unskilled person.

gle tube.

Other objects, a

dvantages and means to effect the same will appear from the followingdescription.

In the accompanying drawing wherein I have illustrated a practicalembodiment of the principles of my invention, 1

Fig. 1 is asectional .view showing a conductor socket without a tubeinserted therein.

Fig. 2 is a view similar tube in place.

Fig. 3 is a view similar to Fig. 2 showing a conductor socket having twopolarimeters.

Fig. 4 is a sectional View taken along the line il of Fig. 3.

Referring to the drawing, l represents the panel of a signboard or thelike on which is mounted the tubular neon socket 2. This socketcomprises the receptacle 3, preferably made of porcelain or likematerial, and the conductor assembly 4.

The receptacle is provided with the fiange 5 and the external thread-edportion 6 which is arranged to be screwed through a hole in the panel Iand secured in place as by the spring nut I. The inner edges of thereceptacle are generally provided with the apertures 8 to permit theescape of dirt and water that may seek its way into the socket.

The center of the inner end of the receptacle is also provided with ahole to receive the threaded bolt 9, the head of which holds the socketfingers Ill in their proper position within the receptacle. The outerend of the bolt 9 is provided with the lock washer II and the nut l2which secures the conductor assembly to the receptacle. 13 represents aterminal nut for securing a lead wire from a transformer or other sourceto the conductor assembly.

The socket fingers H] are preferably made of bronze or similar materialthat will resist corrosicn, provide proper spring pressure and have thedesired electrical characteristics. As shown herein, I provide fourfingers made up from two strips. However, for extraordinary long andheavy neon tubes additional fingers may be added. In assembling thesefingers I prefer to weld or solder these strips together so that theywill maintain their proper spaced relation. If on the other hand morethan one circuit is to be electrically connected to a single tube, thenthese fingers must be insulated from one another, as will be laterexplained.

Referring specifically to the fingers I0, shown in the drawing, it willbe noted that they are provided with the abutments l4 and i5. Theabutment I4 is made fast by the bolt 9, whereas the to Fig. 1 showingthe abutment i5 is arranged to contact the inner surface of the tubularreceptacle 3 and is also preferably free to slide longitudinallythereof.

it and ii represent tube contact or suspension points of the fingerswhich are between the abutments and connected therewith by the spansections i8 and i9. 28 represents the intermediate span section betweenthe contact points 1 ii and II.

The opposing contact points of the several fingers when inactive arespaced apart a distance somewhat less than the diameter of the object tobe grasped to enable the fingers to firmly hold the object asillustrated in Fig. 2.

The span sections it, it and 29 are so constructed as to redirect theforces transmitted from the abutments M and i5 and the contact points itand ii to provide increased radial pressure on the tube when thefingersare expanded by its insertion. When assembled the fingers are providedwith initial spring tension tending to expand them outwardly, therebyforcing the abutment M tighter against the wall of the tubularreceptacle.

The tube 25 may be provided with the metallic adapter shell or base 22to aid in withstanding the pressure exerted by the fingers and alsoserve to conduct the electric current to the elements in the tube. Thisbase may be corrugated or threaded as in the case of a light bulb.However, if the base is cylindrical it is preferable to provide theflange portion 23 on the end which by its engagement with the contactpoints prevent accidental dismounting of the tube.

The proximity of the base 22 to the electrode 24 and the pinch seal 25within the tube is notper se a part of this invention and is thereforenot described in detail.

When the base 22 of the tube 2i is inserted in the socket and past thecontact points It and H, as shown in Fig. 2, the span sections I8, l9and 26 are under compression and the angular parts thereof expand,causing the free abutment iii to creep along the inner wall of thereceptacle. By properly forming the span sections with respect to theinner wall of the receptacle, which may or may not be tapered, thedesired gripping characteristics of the fingers may be produced. Byproviding two tube contacting points on each finger the tube is notpermitted to rock within its socket, which frequently results inbreakage. Again owing to the fact that the two tube contacting points itand ll are suspended between the abutments l4 and E5 the tube in effectis resiliently vmounted. The fingers furnish the proper cushion effectand absorb or substantially prevent the transmission of vibrationsbetween the sign panel and the tube.

Referring to the modification shown in Figs. 3 and i, the strips whichform the two pairs of fingers 26 and 2'5 are insulated from one anotherby means of the interposed member 28 which may be an integral part ofthe receptacle 3 or a separate disk. The bolt 9 thus mechanically holdsthe fingers in place and serves as a terminal for the fingers 25,whereas the bolt 29 serves as the terminal to electrically connect thefingers 2'! through the bus strap 30. Where the bolt 9 passes throughthe central portion of the strip which forms the finger 27 I provide theinsulating washer 3|! The center portion of the span section 20 may bedesigned to rest against the wall of the receptacle as shown in Fig. 3,thus providing an additional abutment to support the contact points itand ll. This arrangement provides additional gripping qualities but isnot as resilient as the form shown in Fig. 2.

With this design it is necessary to provide a shell or base made up infour sections 32, 33, 35 and 35, wherein the opposite sections which areof like polarity may be connected to one another across the base of thetube but insulated from each other and connected to their respectiveelements within the tube. The tube may be grooved longitudinally toreceive these base sections and they may be held in place as bycementing.

This type of socket would be advantageous for mercury tubes and the likewhere a starting electrode of filament is used.

I claim:

1. In a socket, the combination of an open ended housing made ofinsulating material and having a smooth continuous inner wall, agripping finger extending longitudinally within the housing and securedto the closed end thereof, abutments on said finger adjacent the endsthereof and in direct engagement with the wall of the housing forsupporting said finger, and a pair of contact points spacedlongitudinally on said finger intermediate ofsaid abutments for engagingand gripping an inserted object, said outer abutment being in slidingengagement with the inner Wall of the housing.

2. In a socket, the combination of an open ended housing made ofinsulating material and having a smooth continuous inner wall, agripping finger extending longitudinally within the housing and securedto the closed end thereof,

abutments on said finger adjacent the ends thereof and in directengagement with the wall of the housing for supporting Said finger, anda pair of contactpoints spaced longitudinally on said fingerintermediate of said abutments for engaging and gripping an insertedobject, the inner abutment being fixed relative to the housing and theouter abutment being slidable longitudinally of the housing as theobject engages said contact points.

3. In a socket, the combination of an open ended housing made ofinsulating material and having a smooth continuous inner wall, aplurality of gripping fingers extending longitudinally within thehousing and secured to the closed end thereof, abutments on said fingersadjacent the ends thereof and in direct engagement with the wall of thehousing for supporting said fingers, and a plurality of contact pointsspaced longitudinally on said fingers intermediate of said abutments forengaging and gripping an inserted object, said outer abutment being insliding engagement with the inner wall of the housing.

4. In a socket, the combination of an open ended housing made ofinsulating material and having a smooth continuous inner wall, grippingmeans extending longitudinally within the housing and secured to theclosed end of the latter, said means having alternate abutments,lorigitudinally spaced apart and engaging the wall of the housing, andcontact portions for gripping an inserted object, and the innermostabutment being fixed while the remaining abutments are in slidingengagement with the wall of the housing.

5. In a socket, the combination of an open ended housing made ofinsulating material and provided with a smooth bore, gripping meansextending longitudinally therein, the inner end of said gripping meansbeing secured to the inner closed end of the housing, and said grippingmeans being also provided with a plurality of longitudinally spacedabutments in sliding engagement with the bore of the housing, andcontact portions on said gripping means intermediate of said abutmentsand spaced longitudinally thereof for engaging an inserted object.

6. An electric socket for use with a plug member having a plurality ofcontact surfaces mounted on the perimeter thereof, the combination of anopen ended housing made of insulating material and having a smooth bore,a plurality of gripping fingers insulated from each other and extendinglongitudinally within the v housing, said fingers being secured to theclosed end of the housing, abutments on said fingers adjacent their endsand in direct engagement with the wall of the housing, and a pluralityof longitudinally spaced contact points on each finger intermediate ofsaid abutments for engaging and gripping the respective contact surfaceson a lug.

'l. An electric socket for use with a plug member having a plurality ofcontact surfaces mounted on the perimeter, thereof, the combition of anopen ended housing made of insulating material and having a smooth bore,a plurality of gripping fingers extending longitudinally within thehousing and insulated from one another, said fingers being secured tothe closed end of the housing, a plurality of abutments in longitudinalspaced relation on said fingers and in sliding engagement with the wallof the housing, and a plurality of contact points on said fingers, eachcontact point being disposed between adjacent abutments and arranged toengage and grip the respective contact surfaces on a plug.

THOMAS MARTIN.

